A traffic group defines the ingress traffic to which you want to apply some level of QoS. You can use the ExtremeXOS software to define traffic groups based on the following:
- Frame or packet header information such as IP address or MAC address
- CoS 802.1p bits in the frame header
- DiffServ information in a packet header
- Ingress port number
- VLAN ID
Traffic groups that are defined based on frame or packet information are usually defined in Access Control Lists (ACLs). The exception to this rule is the CoS and DiffServ information, which you can use to define traffic groups without ACLs.
The function of the CoS and DiffServ traffic groups is sometimes referred to as explicit packet marking, and it uses information contained within a frame or packet to explicitly determine a class of service. An advantage of explicit packet marking is that the class of service information can be carried throughout the network infrastructure, without repeating what can be complex traffic group policies at each switch location. Another advantage is that end stations can perform their own packet marking on an application-specific basis. Extreme Networks switch products have the capability of observing and manipulating packet marking information with no performance penalty.
The CoS and DiffServ capabilities (on supported platforms) are not impacted by the switching or routing configuration of the switch. For example, 802.1p information can be preserved across a routed switch boundary and DiffServ code points can be observed or overwritten across a Layer 2 switch boundary.
During QoS configuration, you configure the QoS level first by configuring QoS profiles, traffic queues, and meters, and then you define a traffic group and assign the traffic group to the QoS configuration.